USB Host User Configuration

The following USB host configuration must be included in the conf_usb_host.h file of the application:

1. USB_HOST_UHI (List of UHI APIs).

Define the list of UHI supported by USB host. (E.g.: UHI_MSC, UHI_HID_MOUSE).

2. USB_HOST_POWER_MAX (mA).

Maximum current allowed on Vbus.

3. USB_HOST_HS_SUPPORT (Only defined).

Authorize the USB host to run in High Speed.

4. USB_HOST_HUB_SUPPORT (Only defined).

Authorize the USB HUB support.

USB Host User Callback

The following optional USB host callback can be defined in the conf_usb_host.h file of the application:

1. void UHC_MODE_CHANGE (bool b_host_mode).

To notify that the USB mode are switched automatically. This is possible only when ID pin is available.

2. void UHC_VBUS_CHANGE (bool b_present).

To notify that the Vbus level has changed (Available only in USB hardware with Vbus monitoring).

3. void UHC_VBUS_ERROR (void).

To notify that a Vbus error has occurred (Available only in USB hardware with Vbus monitoring).

4. void UHC_CONNECTION_EVENT (uhc_device_t* dev, bool b_present).

To notify that a device has been connected or disconnected.

5. void UHC_WAKEUP_EVENT (void).

Called when a USB device or the host have wake up the USB line.

6. void UHC_SOF_EVENT (void).

Called for each received SOF each 1ms. Available in High and Full speed mode.

7. uint8_t UHC_DEVICE_CONF (uhc_device_t* dev).

Called when a USB device configuration must be chosen. Thus, the application can choose either a configuration number for this device or a configuration number 0 to reject it. If callback not defined the configuration 1 is chosen.

8. void UHC_ENUM_EVENT (uhc_device_t* dev, uint8_t b_status).

Called when a USB device enumeration is completed or failed.

USB Host Setup Steps

USB Host Controller (UHC) - Prerequisites

Common prerequisites for all USB hosts.

This module is based on USB host stack full interrupt driven and supporting sleepmgr. For AVR® and Atmel® | SMART ARM®-based SAM3/4 devices the clock services is supported. For SAM D21 devices the clock driver is supported.

The following procedure must be executed to setup the project correctly:

Specify the clock configuration:
- UC3 and SAM3/4 devices without USB high speed support need 48MHz clock input. You must use a PLL and an external OSC.
- UC3 and SAM3/4 devices with USB high speed support need 12MHz clock input. You must use an external OSC.
- UC3 devices with USBC hardware need CPU frequency higher than 25MHz
- SAM D21 devices without USB high speed support need 48MHz clock input. You must use a DFLL and an external OSC.
In conf_board.h, the define CONF_BOARD_USB_PORT must be added to enable USB lines. (Not mandatory for all boards).
Enable interrupts
Initialize the clock service

The usage of sleep manager service is optional, but recommended to reduce power consumption:

Initialize the sleep manager service
Activate sleep mode when the application is in IDLE state

For AVR and SAM3/4 devices, add to the initialization code:

sysclk_init();
irq_initialize_vectors();
cpu_irq_enable();
board_init();
sleepmgr_init(); // Optional

For SAM D21 devices, add to the initialization code:

system_init();
irq_initialize_vectors();
cpu_irq_enable();
sleepmgr_init(); // Optional

Add to the main IDLE loop:

sleepmgr_enter_sleep(); // Optional

USB Host Controller (UHC) - Example Code

Common example code for all USB hosts.

Content of conf_usb_host.h:

#define USB_HOST_POWER_MAX 500

Add to application C-file:

void usb_init(void)
{
    uhc_start();
}

USB Device Controller (UHC) - Workflow

Common workflow for all USB devices.

Ensure that conf_usb_host.h is available and contains the following configuration which is the main USB device configuration:
// Maximum current allowed on Vbus (mA) which depends of 5V generator

#define USB_HOST_POWER_MAX 500 // (500mA)
Call the USB host stack start function to enable USB Host stack:
uhc_start();

conf_clock.h examples with USB support

Content of conf_clock.h for AT32UC3A0, AT32UC3A1, and AT32UC3B devices (USBB):

// Configuration based on 12MHz external OSC:
#define CONFIG_PLL1_SOURCE          PLL_SRC_OSC0
#define CONFIG_PLL1_MUL             8
#define CONFIG_PLL1_DIV             2
#define CONFIG_USBCLK_SOURCE        USBCLK_SRC_PLL1
#define CONFIG_USBCLK_DIV           1 // Fusb = Fsys/(2 ^ USB_div)

Content of conf_clock.h for AT32UC3A3 and AT32UC3A4 devices (USBB with high speed support):

// Configuration based on 12MHz external OSC:
#define CONFIG_USBCLK_SOURCE        USBCLK_SRC_OSC0
#define CONFIG_USBCLK_DIV           1 // Fusb = Fsys/(2 ^ USB_div)

Content of conf_clock.h for AT32UC3C device (USBC):

// Configuration based on 12MHz external OSC:
#define CONFIG_PLL1_SOURCE          PLL_SRC_OSC0
#define CONFIG_PLL1_MUL             8
#define CONFIG_PLL1_DIV             2
#define CONFIG_USBCLK_SOURCE        USBCLK_SRC_PLL1
#define CONFIG_USBCLK_DIV           1 // Fusb = Fsys/(2 ^ USB_div)
// CPU clock need of clock > 25MHz to run with USBC
#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_PLL1

Content of conf_clock.h for SAM3X and SAM3A devices (UOTGHS: USB OTG High Speed):

// USB Clock Source fixed at UPLL.
#define CONFIG_USBCLK_SOURCE        USBCLK_SRC_UPLL
#define CONFIG_USBCLK_DIV           1

Content of conf_clocks.h for SAM D21 devices (USB):

// USB Clock Source fixed at DFLL.
// SYSTEM_CLOCK_SOURCE_XOSC32K configuration - External 32KHz crystal/clock oscillator
#  define CONF_CLOCK_XOSC32K_ENABLE               true
#  define CONF_CLOCK_XOSC32K_EXTERNAL_CRYSTAL     SYSTEM_CLOCK_EXTERNAL_CRYSTAL
#  define CONF_CLOCK_XOSC32K_STARTUP_TIME         SYSTEM_XOSC32K_STARTUP_65536
#  define CONF_CLOCK_XOSC32K_AUTO_AMPLITUDE_CONTROL  false
#  define CONF_CLOCK_XOSC32K_ENABLE_1KHZ_OUPUT    false
#  define CONF_CLOCK_XOSC32K_ENABLE_32KHZ_OUTPUT  true
#  define CONF_CLOCK_XOSC32K_ON_DEMAND            false
#  define CONF_CLOCK_XOSC32K_RUN_IN_STANDBY       true
// SYSTEM_CLOCK_SOURCE_DFLL configuration - Digital Frequency Locked Loop
#  define CONF_CLOCK_DFLL_ENABLE                  true
#  define CONF_CLOCK_DFLL_LOOP_MODE               SYSTEM_CLOCK_DFLL_LOOP_MODE_CLOSED
#  define CONF_CLOCK_DFLL_ON_DEMAND               true
// DFLL closed loop mode configuration
#  define CONF_CLOCK_DFLL_SOURCE_GCLK_GENERATOR   GCLK_GENERATOR_1
#  define CONF_CLOCK_DFLL_MULTIPLY_FACTOR         (48000000/32768)
#  define CONF_CLOCK_DFLL_QUICK_LOCK              true
#  define CONF_CLOCK_DFLL_TRACK_AFTER_FINE_LOCK   true
#  define CONF_CLOCK_DFLL_KEEP_LOCK_ON_WAKEUP     true
#  define CONF_CLOCK_DFLL_ENABLE_CHILL_CYCLE      true
#  define CONF_CLOCK_DFLL_MAX_COARSE_STEP_SIZE    (0x1f / 8)
#  define CONF_CLOCK_DFLL_MAX_FINE_STEP_SIZE      (0xff / 8)
#  define CONF_CLOCK_CONFIGURE_GCLK               true
// Configure GCLK generator 0 (Main Clock)
#  define CONF_CLOCK_GCLK_0_ENABLE                true
#  define CONF_CLOCK_GCLK_0_RUN_IN_STANDBY        true
#  define CONF_CLOCK_GCLK_0_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_DFLL
#  define CONF_CLOCK_GCLK_0_PRESCALER             1
#  define CONF_CLOCK_GCLK_0_OUTPUT_ENABLE         false
// Configure GCLK generator 1
#  define CONF_CLOCK_GCLK_1_ENABLE                true
#  define CONF_CLOCK_GCLK_1_RUN_IN_STANDBY        false
#  define CONF_CLOCK_GCLK_1_CLOCK_SOURCE          SYSTEM_CLOCK_SOURCE_XOSC32K
#  define CONF_CLOCK_GCLK_1_PRESCALER             1
#  define CONF_CLOCK_GCLK_1_OUTPUT_ENABLE         true

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